find-and-replace.md

Find and Replace

The FIND-AND-REPLACE directive transforms string column values using a "sed"-like expression to find and replace text.

Syntax

find-and-replace <column> <sed-script>

Usage Notes

This directive is a column-oriented text processor that operates on a single value in the given column. The sed-script is applied on each text value to transform the data.

A typical example on how the directive is used:

find-and-replace <column> s/regex/replacement/g

This directive will replace a value of the column that matches the regex with the replacement value.

The s stands for "substitute". The g stands for "global", which means that all matching occurrences in the value would be replaced.

The regular expression to be matched is placed after the first delimiting symbol (a forward-slash in this example) and the replacement value follows the second delimiting symbol. A forward-slash (/) is the conventional symbol used as a delimiter, and the origin of the character for "search".

For example, to replace all occurrences of hello with world in the column message:

find-and-replace message s/hello/world/g

If you want to change a pathname that contains a slash (such as /usr/local/bin to /common/bin), you can use a backslash to escape any slashes:

  find-and-replace column s/\/usr\/local\/bin/\/common\/bin//g

Example

Using this record as an example:

{
  "body": "one two three four five six seven eight"
}

Applying these two directives:

find-and-replace body s/one/ONE/g
find-and-replace body s/two/2/g

would result in this record:

{
  "body": "ONE 2 three four five six seven eight",
}